The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
As shown in FIG. 1, a propulsion unit of a dual-flow turbojet engine comprises typically an outer structure 1 including an upstream part 3 forming an air inlet, an intermediate part 5, the inner skin 6 of which forms a casing for the blower 7 of the engine, and a downstream part 9 which can incorporate reversing thrust means.
This nacelle further includes an inner structure 11 having a fairing 13 of the engine 15.
The volume delimited in particular by the inner skin 6 of the outer structure 1 and by the fairing 13 of the inner structure 11, defines an annular air vein 17, often referred to as “cold air vein”, as opposed to the hot air generated by the engine 15.
The blower 7 consists of a propeller provided with blades 19, rotationally mounted on a rotating shaft connected to and centered on a bearing 21, the bearing 21 is connected to the blower casing 6 by a set of transverse structure 25 identified in FIG. 1, radially extending in the cold air vein 17, such as structural arms able to be distributed to 90 or 120 degrees, for example.
In this same cold air vein 17 is located a flow straightening structure comprising flow straightening vanes 23, also called OGV “Outlet Guide Vanes”, allowing to straighten backward the cold air flow generated by the blower 7.
Concepts in which the wheel of the vanes OGV replaces the structural arms, providing thus the two functions of flow straightening and of connecting the bearing 21 to the blower casing 6 are also known.
Wheels OGV called structural in which the OGVs are metallic are thus known.
Nonstructural composite wheels OGV associated with the metallic structural arms are also known.
The design of composite and structural OGVs, allowing thus to totally or partially overcome structural arms, presents a significant challenge to design and produce the fasteners of these vanes at their ends and the structure continuity of these fasteners with the body of the vanes.